SULFADIMETHOXINE AND ORMETOPRIM ? FIELD EFFECTIVENESS STUDY IN RAINBOW TROUT.RESEARCH STRATEGY Summary PHARMAQ AS holds NADA 125933 for Sulfadimethoxine and Ormetoprim (Romet 30), a Type A Medicated Article for use in feed. Current label indications are for the control of mortality in salmonids against furunculosis disease caused by Aeromonas salmonicida and in channel catifhs against enteric septicemia caused by Edwardsiella ictaluri. PHARMAQ AS desires to expand the label indications for NADA 125933. US FDA Center for Veterinary Medicine drug registration requirements include clinical field studies to address effectiveness of a proposed label indication. The study will follow the proposed study protocol submitted on December 4, 2019, entitled ?The Efficacy of Romet 30 (sulfadimethoxine and ormetoprim Type A medicated article) Administered in Feed to control mortality caused by susceptible bacterial pathogens of freshwater-reared finfish. Specifically, this study will assess the effectiveness of the drug against enteric redmouth disease caused by Yersinia ruckeri in rainbow trout (Oncorhynchus mykiss). The study will be conducted under subaward by US Fish and Wildlife Services, Aquatic Animal Drug Approval Partnership, Bozeman, Montana at an appropriately vetted site undergoing a natural epizootic.